Delete ios_raw_unit.rs (538 lines) and all SonoraExperimental references
from the core audio crate. The experimental RemoteIO path that bypassed
Apple VPIO in favor of software WebRTC APM was never shipped and is no
longer needed. VPIO is the sole production iOS audio backend.
- Delete ios_raw_unit.rs entirely
- Remove Raw variant from IosVoiceBackend enum in engine.rs
- Remove SonoraExperimental from IosVoiceProcessingMode enum
- Simplify validate_for_ios() (single-variant enum, no mode check)
- Remove 2 SonoraExperimental validation tests
- Remove ios_raw_unit module declaration from lib.rs
- Remove include_str!-based debug_wav test for the deleted file
Edison Jwa
3f9ea4f7b8